Preferred Language
Articles
/
OBdc4I4BVTCNdQwCYFl_
Absorption Coefficient of a Double-Layer Inhomogeneous Micro-perforated Panel Backed with Multiple Cavity Depths
...Show More Authors

Double-layer micro-perforated panels (MPPs) have been studied extensively as sound absorption systems to increase the absorption performance of single-layer MPPs. However, existing proposed models indicate that there is still room for improvement regarding the frequency bands of absorption for the double-layer MPP. This study presents a double-layer MPP formed with two single MPPs with inhomogeneous perforation backed by multiple cavities of varying depths. The theoretical formulation is developed using the electrical equivalent circuit method to calculate the absorption coefficient under a normal incident sound. The simulation results show that the proposed model can produce absorption coefficient with wider absorption bandwidth compared with the conventional double- and even triple-layer MPPs. The bandwidth can be increased to higher frequency by decreasing the cavity depth behind a sub-MPP with small hole diameter and a high perforation ratio, and to lower frequency by increasing the cavity depth behind a sub-MPP with large hole diameter and a small perforation ratio. The experimental data, measured by impedance tube, are in good agreement with the predicted results.

Scopus Clarivate Crossref
View Publication
Publication Date
Wed Dec 30 2015
Journal Name
Al-kindy College Medical Journal
Application of Alvarado scoring system in the diagnosis of acute appendicitis.
...Show More Authors

Background: Acute appendicitis is the most common abdominal surgical emergency. The diagnosis of this condition is still essentially clinical and there is difficulty in the clinical diagnosis, especially among elderly, children and patients with a typical presentation, so early and accurate diagnosis of acute appendicitis is important to avoid its complications.Objectives: To evaluate the degree of accuracy of Alvarado scoring system in the diagnosis of acute appendicitis.Method: Two hundred patients were admitted to the Alkindy Teaching Hospital from January 2011 to april 2014- presented with symptoms and signs suggestive of acute appendicitis. After examination and investigations all patients were given a score according to Alvarado sc

... Show More
View Publication Preview PDF
Publication Date
Sun Apr 30 2017
Journal Name
Journal Of Engineering
Effect of Construction Joints on the Behavior of Reinforced Concrete Beams
...Show More Authors

In this study, the effect of construction joints on the performance of reinforced concrete beams was experimentally investigated. Seven beam specimens, with dimensions of 200×100×1000 mm, were fabricated. The variables were considered including; the location and configuration of the joints. One beam was cast without a joint (Reference specimen), two specimens were fabricated with a one horizontal joint located either at tension, or compression zone. The fourth
beam had two horizontal joints placed at tension, and compression area. The remaining specimens were with one or two inclined joints positioned at the shear span or beam’s mid-span. The specimens were subjected to a monotonic central concentrated loading until the failure. T

... Show More
View Publication Preview PDF
Publication Date
Wed Jan 04 2017
Journal Name
Applied Research Journal
ASSESSMENT OF SHEAR AND COMPRESSIBILITY PROPERTIES OF ASPHALT STABILIZED COLLAPSIBLE SOIL
...Show More Authors

One of the major problems facing the road construction engineer is the collapsible granular soil which may be used for embankment construction. Problems appears when such compacted soil come in touch with water, it exhibits cracking and uncontrolled settlement. Collapsible soils are defined as any unsaturated soil that goes through a radical rearrangement of practice and great loss of volume upon wetting, with or without additional loading. An attempt has been made in this investigation to stabilize the collapsible soil of Nasiriya with asphalt emulsion. Specimens of pure and asphalt emulsion stabilized soil have been prepared using optimum fluid content and tested. The first group of specimens of (60x60x20) cm have been tested for direct s

... Show More
Publication Date
Sun Jan 13 2019
Journal Name
Iraqi Journal Of Physics
Quantum mechanical study of electronic properties of zigzag nanotubes (9,0) (SWCNTs)
...Show More Authors

Quantum calculations on the most stable structure were carried
out for calculating the electronic properties, energies and the charge
density at the Carbon and Hydrogen atoms by Semi-empirical
method (PM3) of zigzag carbon nano tube CNT (9,0) (SWCNTs), at
the equilibrium geometry depending on the pictures of Zigzag
CNT(9,0) which was found to has D3d symmetry point group by
applying for (Gaussian 2003) program. In this work the results
include calculation the relation for axial bonds length, which are the
vertical C-C bonds (annular bonds) in the rings and bonds length
which are in the outer ring that called the circumferential bonds. Also
include a different kind of vibration modes like breathing, puckering

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Jun 30 2013
Journal Name
Al-khwarizmi Engineering Journal
Estimation of SNR Including Quantization Error of Multi-Wavelength Lidar Receiver
...Show More Authors

 This paper comprises the design and operation of mono-static backscatter lidar station based on a pulsed Nd: YAG laser that operates at multiple wavelengths. The three-color lidar laser transmitter is based on the collinear fundamental 1064 nm, second harmonic 532 nm and a third harmonic 355nm output of a Nd:YAG laser. The most important parameter of lidar especially daytime operations is the signal-to-noise ratio (SNR) which gives some instructions in designing of lidar and it is often limit the effective range. The reason is that noises or interferences always badly affect the measured results. The inversion algorithms have been developed for the study of atmospheric aerosols. Signal-to-noise ratio (SNR) of three-color channel re

... Show More
View Publication Preview PDF
Publication Date
Fri Jul 01 2022
Journal Name
Journal Of Engineering
Influence of Stone Powder on the Mechanical Properties of Clayey Soil
...Show More Authors

In this experimental study, the use of stone powder as a stabilizer to the clayey soil studied. Tests of Atterberg limits, compaction, fall cone (FCT), Laboratory vane shear (LVT), and expansion index (EI) were carried out on soil-stone powder mixtures with fixed ratios of stone powder (0%, 5%, 10%, 15%, and 20%) by the dry weight. Results indicated that the undrained shear strength obtained from FCT and LVT increased at all the admixture ratios, and the expansion index reduced with the increase of the stone powder.

View Publication Preview PDF
Crossref
Publication Date
Wed May 24 2023
Journal Name
College Of Islamic Sciences
Metaphor in the interpretation of the long sea of Ibn Ajiba
...Show More Authors

Scientists have delved too much into reality and metaphor, and perhaps a topic of Arabic rhetoric has not received the attention and care of scholars as much as the topic of truth and metaphor. The metaphor opens wide horizons of expression in front of the writer so that he has several means by which he can express the one experience, so his imagination takes off depicting the intelligible as tangible, the seen as audible, and the audible as seen. That image presented by the creative writer.
The first thing to note is that the emergence of metaphor as a rhetorical term was at the hands of the Mu'tazila. Muslims differed about the issue of metaphor in the Holy Qur’an, and the beginning of the dispute was about the verses in which the

... Show More
View Publication
Publication Date
Tue Nov 08 2022
Journal Name
Aip Conference Proceedings
Prevalence of common skin diseases among outpatients clinic of Baghdad hospital
...Show More Authors

Abstract. Healthy skin is an important layer that gives appearance and self-confidence. The skin is affected by internal and external factors that surrounding the body. The problem of skin diseases is considered as one of the widespread diseases. The occurrence of these diseases varies from place to place depending on the nature of climate, the culture of the people, and their economic condition. A cross-sectional study of skin diseases was conducted at the dermatology centre for outpatient clinic of Baghdad hospital. The study is based on 7555 patients of all ages who are attended to this hospital in order to determine the prevalence of skin diseases. The study shows that the most prevalence skin diseases were infectious diseases with

... Show More
Scopus Crossref
Publication Date
Mon Mar 08 2021
Journal Name
Baghdad Science Journal
Some properties of the Osvillatory and nonoscillatory solutions of second order
...Show More Authors

in this paper sufficient conditions of oscillation of all of nonlinear second order neutral differential eqiation and sifficient conditions for nonoscillatory soloitions to onverage to zero are obtained

View Publication Preview PDF
Crossref
Publication Date
Sun May 10 2020
Journal Name
Baghdad Science Journal
In Silico Analysis of Regulatory Elements of the Vitamin D Receptor
...Show More Authors

Vitamin D receptor (VDR) is a nuclear transcription factor that controls gene expression. Its impaired expression was found to be related to different diseases. VDR also acts as a regulator of different pathways including differentiation, inflammation, calcium and phosphate absorption, etc. but there is no sufficient knowledge about the regulation of the gene itself. Therefore, a better understanding of the genetic and epigenetic factors regulating the VDR may facilitate the improvement of strategies for the prevention and treatment of diseases associated with dysregulation of VDR. In the present investigation, a set of databases and methods were used to identify putative functional elements in the VDR locus. Histone modifications, CpG I

... Show More
View Publication Preview PDF
Scopus (4)
Scopus Clarivate Crossref